Polyolefin-Based Crosslinked Articles

ABSTRACT

Methods for making a crosslinked elastomeric composition and articles made of the same are provided. In at least one specific embodiment, an elastomeric composition comprising at least one propylene-based polymer is blended with at least one component selected from the group consisting of multifunctional acrylates, multifunctional methacrylates, functionalized polybutadiene resins, functionalized cyanurate, and allyl isocyanurate; and blended with at least one component selected from the group consisting of hindered phenols, phosphites, and hindered amines. The propylene-based polymer can include propylene derived units and one or more dienes, and have a triad tacticity of from 50% to 99% and a heat of fusion of less than 80 J/g. The blended composition can then be extruded and crosslinked. The extruded polymer can be crosslinked using electron beam radiation having an e-beam dose of about 100 KGy or less. The crosslinked polymers are particularly useful for making fibers and films.

FIELD OF INVENTION

Embodiments of the present invention relate to crosslinked elastomericcompositions, articles, and methods for making same. More particularly,embodiments of the present invention relate to fibers and films producedfrom crosslinked propylene-based polymers.

BACKGROUND

Materials with good stretchability and elasticity are used tomanufacture a variety of disposable articles in addition to durablearticles including incontinence pads, disposable diapers, trainingpants, clothing, undergarments, sports apparel, automotive trim,weather-stripping, gaskets, and furniture upholstery. For clothing,stretchability and elasticity are performance attributes that allow thematerials to provide a closely conforming fit to the body of the wearer.

While numerous materials are known to exhibit excellent stress-strainproperties and elasticity at room temperatures, it is often desirablefor elastic materials to provide a conforming or secure fit duringrepeated use, during extensions and retractions at elevated or depressedtemperatures, or in automobile interiors during summer months.Elasticity at elevated temperatures is also important for maintainingtight tolerances throughout temperature cycles. In particular, elasticmaterials used for repeated wear clothing or garments must maintaintheir integrity and elastic performance after laundering.

Spandex™, a segmented polyurethane urea elastic material, is currentlyused in various durable fabrics. For example, fibers made from Spandex™have been used in launderable apparels, fabrics, durable and disposablefurnishing, beddings, etc. Similar to conventional uncrosslinkedpolyolefin-based elastic materials, articles made from Spandex™ can loseintegrity, shape, and elastic properties when subjected to elevatedtemperatures. Thus, Spandex™ is not suitable for many co-knittingapplications with high temperature fibers, such as polyester fibers.

Propylene-based polymers having good elastic properties are known andhave been used for stretchable clothing. See, for example, U.S. Pat. No.6,525,157 and U.S. Pat. No. 6,342,565. U.S. Pat. No. 6,342,565, inparticular, discloses a soft, set-resistant, annealed fiber comprising ablend of polyolefins. The blend has a flexural modulus less than orequal to 12,000 psi and includes from 75 to 98 wt % of a first polymercomponent and from 2 to 25 wt % of a second polymer component. The firstpolymer component is a propylene-ethylene polymer having at least 80 wt% propylene and up to 20 wt % ethylene, a melting point by DSC in therange of from 25 to 70° C., and a heat of fusion less than 25 J/g. Thesecond polymer component is a stereoregular isotactic polypropylenehaving a melting point by DSC of greater than 130° C., and a heat offusion greater than 120 J/g. The fiber exhibits a resistance to setequal to or less than 80% from a 400% tensile deformation. Thepolyolefin blend is said to be substantially non-crosslinked.

U.S. Pat. No. 6,500,563 discloses blends of two different types ofpolypropylene, including blends made from a polypropylene having a Tm ofless than 110° C. and propylene-ethylene copolymer that hasisotactically arranged propylene derived sequences and Tm less than 105°C.

Three component blends of isotactic polypropylene, impact modifyingamounts of an ethylene-propylene based rubber or low density ethylenecopolymer and a propylene-based elastomer as compatibilizer aredescribed in EP946640, EP964641, EP969043 and EP1098934.

WO04/014988 describes blends of isotactic polypropylene withnon-functionalized plasticizers such as poly-alpha-olefins. WO03/040233also discloses two component blends with the isotactic polypropylene asthe predominant, matrix phase and the propylene-based copolymer servingas an impact modifier.

EP1003814 and U.S. Pat. No. 6,642,316 disclose two-component blends ofsmall amounts of isotactic polypropylene and predominant amounts of anethylene based elastomer. EP0374695 discloses visually homogeneous twocomponent blends however using 40 wt % or less of the propylene-basedcopolymer. WO 00/69963 describes films made of two-component blends withfrom 75 to 98 wt % of a propylene ethylene based elastomer having a heatof fusion of less than 25 J/g.

Other related references include US Publication Numbers 2006/102149US2005/0107529; 2005/0107530; 2005/0131142; and 2005/0107534.

There is still a need for new and improved propylene-based materialsrequiring good stretchability and elasticity.

SUMMARY OF THE INVENTION

Methods for making a crosslinked elastomeric composition and articlesmade of the same are provided. The crosslinked elastomeric compositioncan be made from blending one or more propylene-based polymers, one ormore antioxidants, and one or more co-agents that when crosslinked,surprisingly and unexpectedly exhibits little to no loss in tensilestrength. In fact, the tensile strength of the crosslinked compositionsurprisingly and unexpectedly improves. Furthermore, the crosslinkedcomposition surprisingly and unexpectedly exhibits excellent setproperties for making fibers and films among other articles. Theelastomeric composition can optionally include one or more polyolefinicthermoplastic resins and/or optionally one or more secondary elastomericcomponents.

In at least one specific embodiment, an elastomeric compositioncomprising at least one propylene-based polymer is blended with at leastone component selected from the group consisting of multifunctionalacrylates, multifunctional methacrylates, functionalized polybutadieneresins, functionalized cyanurate, and allyl isocyanurate; and at leastone component selected from the group consisting of hindered phenols,phosphites, and hindered amines. The propylene-based polymer can includepropylene derived units and one or more dienes, and have a triadtacticity of from 50% to 99% and a heat of fusion of less than 80 J/g.The blended composition can then be extruded and crosslinked. Theextruded polymer can be crosslinked using electron beam radiation havingan e-beam dose of about 200 kGy or less.

In at least one other specific embodiment, at least one propylene-basedpolymer comprising propylene derived units and one or more dienes, thepropylene-based polymer having a triad tacticity of from 50% to 99% anda heat of fusion of less than 80 J/g is blended with one or morepolyolefinic thermoplastic components; at least one component selectedfrom the group consisting of multifunctional acrylates, multifunctionalmethacrylates, functionalized polybutadiene resins, functionalizedcyanurate, and allyl isocyanurate; and at least one component selectedfrom the group consisting of hindered phenols, phosphites, and hinderedamines. The blended composition can be extruded and crosslinked. Theextruded polymer can be crosslinked using electron beam radiation havingan e-beam dose of about 200 kGgy or less.

In at least one other specific embodiment, a method for making acrosslinked elastomeric article comprises blending an elastomericcomposition comprising: at least one propylene-based polymer comprisingpropylene derived units and one or more dienes, the propylene-basedpolymer having a triad tacticity of from 50% to 99% and a heat of fusionof less than 80 J/g; at least one component selected from the groupconsisting of multifunctional acrylates, multifunctional methacrylates,functionalized polybutadiene resins, functionalized cyanurate, and allylisocyanurate; and at least one component comprising trimethylolpropanetrimethacrylate. The blended composition can be extruded andcrosslinked. The extruded polymer can be crosslinked using electron beamradiation having an e-beam dose of about 200 kGgy or less.

In at least one other specific embodiment, the crosslinked elastomericcomposition includes at least one propylene-based polymer comprisingpropylene derived units and one or more dienes, the propylene-basedpolymer having a triad tacticity of from 50% to 99% and a heat of fusionof less than 80 J/g; at least one component selected from the groupconsisting of multifunctional acrylates, multifunctional methacrylates,functionalized polybutadiene resins, functionalized cyanurate, and allylisocyanurate; at least one component comprising trimethylolpropanetrimethacrylate; one or more polyolefinic thermoplastic components; andoptionally one or more secondary elastomeric components, wherein thecrosslinked polypropylene has great than 50% xylene insolubles asmeasured according to ASTM-D 5492.

The crosslinked elastomeric compositions are particularly useful formaking fibers and films.

DETAILED DESCRIPTION

A detailed description will now be provided. Each of the appended claimsdefines a separate invention, which for infringement purposes isrecognized as including equivalents to the various elements orlimitations specified in the claims. Depending on the context, allreferences below to the “invention” may in some cases refer to certainspecific embodiments only. In other cases it will be recognized thatreferences to the “invention” will refer to subject matter recited inone or more, but not necessarily all, of the claims. Each of theinventions will now be described in greater detail below, includingspecific embodiments, versions and examples, but the inventions are notlimited to these embodiments, versions or examples, which are includedto enable a person having ordinary skill in the art to make and use theinventions, when the information in this patent is combined withavailable information and technology.

Propylene-Based Polymer

The propylene-based polymer can be one or more propylene-a-olefin-dieneterpolymers or propylene-diene copolymers. For simplicity and ease ofdescription, however, the terms “propylene-based polymer” and “propylenecopolymer” and “PCP” as used herein will refer to bothpropylene-a-olefin-diene terpolymers and propylene-diene copolymers.

In at least one specific embodiment, the propylene-based polymer can beprepared by polymerizing propylene with one or more dienes. In at leastone other specific embodiment, the propylene-based polymer can beprepared by polymerizing propylene with ethylene and/or at least oneC₄-C₂₀ α-olefin, or a combination of ethylene and at least one C₄-C₂₀α-olefin and one or more dienes. The one or more dienes can beconjugated or non-conjugated. Preferably, the one or more dienes arenon-conjugated.

The comonomers can be linear or branched. Preferred linear comonomersinclude ethylene or C₄ to C₈ α-olefins, more preferably ethylene,1-butene, 1-hexene, and 1-octene, even more preferably ethylene or1-butene. Preferred branched comonomers include 4-methyl-1-pentene,3-methyl-1-pentene, and 3,5,5-trimethyl-1-hexene. In one or moreembodiments, the comonomer can include styrene.

Illustrative dienes can include but are not limited to5-ethylidene-2-norbornene (ENB); 1,4-hexadiene; 5-methylene-2-norbornene(MNB); 1,6-octadiene; 5-methyl-1,4-hexadiene;3,7-dimethyl-1,6-octadiene; 1,3-cyclopentadiene; 1,4-cyclohexadiene;vinyl norbornene (VNB); dicyclopendadiene (DCPD), and combinationsthereof. Preferably, the diene is ENB.

Preferred methods and catalysts for producing the propylene-basedpolymers are found in publications US 2004/0236042 and WO 05/049672 andin U.S. Pat. No. 6,881,800, which are all incorporated by referenceherein. Pyridine amine complexes, such as those described in WO03/040201are also useful to produce the propylene-based polymers useful herein.The catalyst can involve a fluxional complex, which undergoes periodicintra-molecular re-arrangement so as to provide the desired interruptionof stereoregularity as in U.S. Pat. No. 6,559,262. The catalyst can be astereorigid complex with mixed influence on propylene insertion, seeRieger EP1070087. The catalyst described in EP1614699 could also be usedfor the production of backbones suitable for the invention.

The propylene-based polymer can have an average propylene content on aweight percent basis of from about 60 wt % to about 99.7 wt %, morepreferably from about 60 wt % to about 99.5 wt %, more preferably fromabout 60 wt % to about 97 wt %, more preferably from about 60 wt % toabout 95 wt % based on the weight of the polymer. In one embodiment, thebalance comprises diene. In another embodiment, the balance comprisesone or more dienes and one or more of the α-olefins describedpreviously. Other preferred ranges are from about 80 wt % to about 95 wt% propylene, more preferably from about 83 wt % to about 95 wt %propylene, more preferably from about 84 wt % to about 95 wt %propylene, and more preferably from about 84 wt % to about 94 wt %propylene based on the weight of the polymer. The balance of thepropylene-based polymer comprises a diene and optionally, one or morealpha-olefins. In one or more embodiments above or elsewhere herein, thealpha-olefin is ethylene, butene, hexene or octene. In otherembodiments, two alpha-olefins are present, preferably ethylene and oneof butene, hexene or octene.

Preferably, the propylene-based polymer comprises about 0.2 wt % toabout 24 wt %, of a non-conjugated diene based on the weight of thepolymer, more preferably from about 0.5 wt % to about 12 wt %, morepreferably about 0.6 wt % to about 8 wt %, and more preferably about 0.7wt % to about 5 wt %. In other embodiments, the diene content rangesfrom about 0.2 wt % to about 10 wt %, more preferably from about 0.2 toabout 5 wt %, more preferably from about 0.2 wt % to about 4 wt %,preferably from about 0.2 wt % to about 3.5 wt %, preferably from about0.2 wt % to about 3.0 wt %, and preferably from about 0.2 wt % to about2.5 wt % based on the weight of the polymer. In one or more embodimentsabove or elsewhere herein, the propylene-based polymer comprises ENB inan amount of from about 0.5 to about 4 wt %, more preferably from about0.5 to about 2.5 wt %, and more preferably from about 0.5 to about 2.0wt %.

In other embodiments, the propylene-based polymer preferably comprisespropylene and diene in one or more of the ranges described above withthe balance comprising one or more C₂ and/or C₄-C₂₀ olefins. In general,this will amount to the propylene-based polymer preferably comprisingfrom about 5 to about 40 wt % of one or more C₂ and/or C₄-C₂₀ olefinsbased the weight of the polymer. When C₂ and/or a C₄-C₂₀ olefins arepresent the combined amounts of these olefins in the polymer ispreferably at least about 5 wt % and falling within the ranges describedherein. Other preferred ranges for the one or more α-olefins includefrom about 5 wt % to about 35 wt %, more preferably from about 5 wt % toabout 30 wt %, more preferably from about 5 wt % to about 25 wt %, morepreferably from about 5 wt % to about 20 wt %, more preferably fromabout 5 to about 17 wt % and more preferably from about 5 wt % to about16 wt %.

The propylene-based polymer can have a weight average molecular weight(Mw) of 5,000,000 or less, a number average molecular weight (Mn) ofabout 3,000,000 or less, a z-average molecular weight (Mz) of about10,000,000 or less, and a g′ index of 0.95 or greater measured at theweight average molecular weight (Mw) of the polymer using isotacticpolypropylene as the baseline, all of which can be determined by sizeexclusion chromatography, e.g., 3D SEC, also referred to as GPC-3D asdescribed herein.

In one or more embodiments above or elsewhere herein, thepropylene-based polymer can have a Mw of about 5,000 to about 5,000,000g/mole, more preferably a Mw of about 10,000 to about 1,000,000, morepreferably a Mw of about 20,000 to about 500,000, more preferably a Mwof about 50,000 to about 400,000, wherein Mw is determined as describedherein.

In one or more embodiments above or elsewhere herein, thepropylene-based polymer can have a Mn of about 2,500 to about 2,500,000g/mole, more preferably a Mn of about 5,000 to about 500,000, morepreferably a Mn of about 10,000 to about 250,000, more preferably a Mnof about 25,000 to about 200,000, wherein Mn is determined as describedherein.

In one or more embodiments above or elsewhere herein, thepropylene-based polymer can have a Mz of about 10,000 to about 7,000,000g/mole, more preferably a Mz of about 50,000 to about 1,000,000, morepreferably a Mz of about 80,000 to about 700,000, more preferably a Mzof about 100,000 to about 500,000, wherein Mz is determined as describedherein.

The molecular weight distribution index (MWD=(Mw/Mn)), sometimesreferred to as a “polydispersity index” (PDI), of the propylene-basedpolymer can be about 1.5 to 40. In an embodiment the MWD can have anupper limit of 40, or 20, or 10, or 5, or 4.5, and a lower limit of 1.5,or 1.8, or 2.0. In one or more embodiments above or elsewhere herein,the MWD of the propylene-based polymer is about 1.8 to 5 and mostpreferably about 1.8 to 3. Techniques for determining the molecularweight (Mn and Mw) and molecular weight distribution (MWD) can be foundin U.S. Pat. No. 4,540,753 (Cozewith, Ju and Verstrate) (which isincorporated by reference herein for purposes of U.S. practices) andreferences cited therein, in Macromolecules, 1988, volume 21, p 3360(Verstrate et al.), which is herein incorporated by reference forpurposes of U.S. practice, and references cited therein, and inaccordance with the procedures disclosed in U.S. Pat. No. 6,525,157,column 5, lines 1-44, which patent is hereby incorporated by referencein its entirety.

In one or more embodiments above or elsewhere herein, thepropylene-based polymer can have a g′ index value of 0.95 or greater,preferably at least 0.98, with at least 0.99 being more preferred,wherein g′ is measured at the Mw of the polymer using the intrinsicviscosity of isotactic polypropylene as the baseline. For use herein,the g′ index is defined as:

$g^{\prime} = \frac{\eta_{b}}{\eta_{l}}$

where η_(b) is the intrinsic viscosity of the propylene-based polymerand η₁ is the intrinsic viscosity of a linear polymer of the sameviscosity-averaged molecular weight (M_(v)) as the propylene-basedpolymer. η₁=KM_(v) ^(α), K and α were measured values for linearpolymers and should be obtained on the same instrument as the one usedfor the g′ index measurement.

In one or more embodiments above or elsewhere herein, thepropylene-based polymer can have a density of about 0.85 g/cm³ to about0.92 g/cm³, more preferably, about 0.87 g/cm³ to 0.90 g/cm³, morepreferably about 0.88 g/cm³ to about 0.89 g/cm³ at room temperature asmeasured per the ASTM D-1505 test method.

In one or more embodiments above or elsewhere herein, thepropylene-based polymer can have a melt flow rate (MFR, 2.16 kg weight(230° C.), equal to or greater than 0.2 g/10 min as measured accordingto the ASTM D-1238(A) test method as modified (described below).Preferably, the MFR (2.16 kg (230° C.) is from about 0.5 g/10 min toabout 200 g/10 min and more preferably from about 1 g/10 min to about100g/10 min. In an embodiment, the propylene-based polymer has an MFR of0.5 g/10 min to 200 g/10 min, especially from 2 g/10 min to 30 g/10 min,more preferably from 5 g/10 min to 30 g/10 min, more preferably 10 g/10min to 30 g/10 min, more preferably 10 g/10 min to about 25 g/10 min, ormore preferably 2 g/10 min to about 10 g/10 min.

The propylene-based polymer can have a Mooney viscosity ML (1+4) 125°C., as determined according to ASTM D1646, of less than 100, morepreferably less than 75, even more preferably less than 60, mostpreferably less than 30.

In one or more embodiments above or elsewhere herein, thepropylene-based polymer can have a heat of fusion (Hf) determinedaccording to the DSC procedure described later, which is greater than orequal to about 0.5 Joules per gram (J/g), and is ≦about 80 J/g,preferably ≦about 75 J/g, preferably ≦about 70 J/g, more preferably≦about 60 J/g, more preferably ≦about 50 J/g, more preferably ≦about 35J/g. Also preferably, the propylene-based polymer has a heat of fusionthat is greater than or equal to about 1 J/g, preferably greater than orequal to about 5 J/g. In another embodiment, the propylene-based polymercan have a heat of fusion (Hf), which is from about 0.5 J/g to about 75J/g, preferably from about 1 J/g to about 75 J/g, more preferably fromabout 0.5 J/g to about 35 J/g. Preferred propylene-based polymers andcompositions can be characterized in terms of both their melting points(Tm) and heats of fusion, which properties can be influenced by thepresence of comonomers or steric irregularities that hinder theformation of crystallites by the polymer chains. In one or moreembodiments, the heat of fusion ranges from a lower limit of 1.0 J/g, or1.5 J/g, or 3.0 J/g, or 4.0 J/g, or 6.0 J/g, or 7.0 J/g, to an upperlimit of 30 J/g, or 35 J/g, or 40 J/g, or 50 J/g, or 60 J/g or 70 J/g,or 75 J/g, or 80 J/g.

The crystallinity of the propylene-based polymer can also be expressedin terms of percentage of crystallinity (i.e. % crystallinity). In oneor more embodiments above or elsewhere herein, the propylene-basedpolymer has a % crystallinity of from 0.5% to 40%, preferably 1% to 30%,more preferably 5% to 25% wherein % crystallinity is determinedaccording to the DSC procedure described below. In another embodiment,the propylene-based polymer preferably has a crystallinity of less than40%, preferably about 0.25% to about 25%, more preferably from about0.5% to about 22%, and most preferably from about 0.5% to about 20%. Asdisclosed above, the thermal energy for the highest order ofpolypropylene is estimated at 189 J/g (i.e., 100% crystallinity is equalto 209 J/g.).

In addition to this level of crystallinity, the propylene-based polymerpreferably has a single broad melting transition. However, thepropylene-based polymer can show secondary melting peaks adjacent to theprincipal peak, but for purposes herein, such secondary melting peaksare considered together as a single melting point, with the highest ofthese peaks (relative to baseline as described herein) being consideredthe melting point of the propylene-based polymer.

The propylene-based polymer preferably has a melting point (measured byDSC) of equal to or less than 100° C., preferably less than 90° C.,preferably less than 80° C., more preferably less than or equal to 75°C., preferably from about 25° C. to about 80° C., preferably about 25°C. to about 75° C., more preferably about 30° C. to about 65° C.

The Differential Scanning Calorimetry (DSC) procedure can be used todetermine heat of fusion and melting temperature of the propylene-basedpolymer. The method is as follows: about 0.5 grams of polymer is weighedout and pressed to a thickness of about 15-20 mils (about 381-508microns) at about 140° C.-150° C., using a “DSC mold” and Mylar as abacking sheet. The pressed pad is allowed to cool to ambient temperatureby hanging in air (the Mylar is not removed). The pressed pad isannealed at room temperature (23-25° C.) for about 8 days. At the end ofthis period, an about 15-20 mg disc is removed from the pressed padusing a punch die and is placed in a 10 microliter aluminum sample pan.The sample is placed in a Differential Scanning Calorimeter (PerkinElmer Pyris 1 Thermal Analysis System) and is cooled to about −100° C.The sample is heated at 10° C./min to attain a final temperature ofabout 165° C. The thermal output, recorded as the area under the meltingpeak of the sample, is a measure of the heat of fusion and can beexpressed in Joules per gram of polymer and is automatically calculatedby the Perkin Elmer System. The melting point is recorded as thetemperature of the greatest heat absorption within the range of meltingof the sample relative to a baseline measurement for the increasing heatcapacity of the polymer as a function of temperature.

The propylene-based polymer can have a triad tacticity of threepropylene units, as measured by ¹³C NMR of 75% or greater, 80% orgreater, 82% or greater, 85% or greater, or 90% or greater. Preferredranges include from about 50 to about 99%, more preferably from about 60to about 99%, more preferably from about 75 to about 99% and morepreferably from about 80 to about 99%; and in other embodiments fromabout 60 to about 97%. Triad tacticity is determined by the methodsdescribed in U.S. Patent Application Publication 20040236042.

In one or more embodiments above or elsewhere herein, thepropylene-based polymer can be a blend of discrete randompropylene-based polymers. Such blends can include ethylene-basedpolymers and propylene-based polymers, or at least one of each suchethylene-based polymers and propylene-based polymers. The number ofpropylene-based polymers can be three or less, more preferably two orless.

In one or more embodiments above or elsewhere herein, thepropylene-based polymer can include a blend of two propylene-basedpolymers differing in the olefin content, the diene content, or both.

In one or more embodiments above or elsewhere herein, thepropylene-based polymer can include a propylene based elastomericpolymer produced by random polymerization processes leading to polymershaving randomly distributed irregularities in stereoregular propylenepropagation. This is in contrast to block copolymers in whichconstituent parts of the same polymer chains are separately andsequentially polymerized.

In another embodiment, the propylene-based polymers can includecopolymers prepared according the procedures in WO 02/36651. Likewise,the propylene-based polymer can include polymers consistent with thosedescribed in WO 03/040201, WO 03/040202, WO 03/040095, WO 03/040201, WO03/040233, and/or WO 03/040442. Additionally, the propylene-basedpolymer can include polymers consistent with those described in EP 1 233191, and U.S. Pat. No. 6,525,157, along with suitable propylene homo-and copolymers described in U.S. Pat. No. 6,770,713 and U.S. PatentApplication Publication 2005/215964, all of which are incorporated byreference. The propylene-based polymer can also include one or morepolymers consistent with those described in EP 1 614 699 or EP 1 017729.

Grafted (Functionalized) Backbone

In one or more embodiments, the propylene-based polymer can be grafted(i.e. “functionalized”) using one or more grafting monomers. As usedherein, the term “grafting” denotes covalent bonding of the graftingmonomer to a polymer chain of the propylene-based polymer.

The grafting monomer can be or include at least one ethylenicallyunsaturated carboxylic acid or acid derivative, such as an acidanhydride, ester, salt, amide, imide, acrylates or the like.Illustrative monomers include but are not limited to acrylic acid,methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconicacid, mesaconic acid, maleic anhydride, 4-methylcyclohexene-1,2-dicarboxylic acid anhydride,bicyclo(2.2.2)octene-2,3-dicarboxylic acid anhydride,1,2,3,4,5,8,9,10-octahydronaphthalene-2,3-dicarboxylic acid anhydride,2-oxa-1,3-diketospiro(4.4)nonene, bicyclo(2.2.1)heptene-2,3-dicarboxylicacid anhydride, maleopimaric acid, tetrahydrophthalic anhydride,norbornene-2,3-dicarboxylic acid anhydride, nadic anhydride, methylnadic anhydride, himic anhydride, methyl himic anhydride, and5-methylbicyclo(2.2.1)heptene-2,3-dicarboxylic acid anhydride. Othersuitable grafting monomers include methyl acrylate and higher alkylacrylates, methyl methacrylate and higher alkyl methacrylates, acrylicacid, methacrylic acid, hydroxy-methyl methacrylate, hydroxyl-ethylmethacrylate and higher hydroxy-alkyl methacrylates and glycidylmethacrylate. Maleic anhydride is a preferred grafting monomer.

In one or more embodiments, the grafted propylene based polymercomprises from about 0.5 to about 10 wt % ethylenically unsaturatedcarboxylic acid or acid derivative, more preferably from about 0.5 toabout 6 wt %, more preferably from about 0.5 to about 3 wt %; in otherembodiments from about 1 to about 6 wt %, more preferably from about 1to about 3 wt %. In a preferred embodiment wherein the graft monomer ismaleic anhydride, the maleic anhydride concentration in the graftedpolymer is preferably in the range of about 1 to about 6 wt. %,preferably at least about 0.5 wt. % and highly preferably about 1.5 wt.%.

Styrene and derivatives thereof such as paramethyl styrene, or otherhigher alkyl substituted styrenes such as t-butyl styrene can be used asa charge transfer agent in presence of the grafting monomer to inhibitchain scissioning. This allows further minimization of the beta scissionreaction and the production of a higher molecular weight grafted polymer(MFR=1.5).

Preparing Grafted Propylene-Based Polymers

The grafted propylene-based polymer can be prepared using conventionaltechniques. For example, the graft polymer can be prepared in solution,in a fluidized bed reactor, or by melt grafting. A preferred graftedpolymer can be prepared by melt blending in a shear-imparting reactor,such as an extruder reactor. Single screw but preferably twin screwextruder reactors such as co-rotating intermeshing extruder orcounter-rotating non-intermeshing extruders but also co-kneaders such asthose sold by Buss are especially preferred.

In one or more embodiments, the grafted polymer can be prepared by meltblending the ungrafted propylene-based polymer with a free radicalgenerating catalyst, such as a peroxide initiator, in the presence ofthe grafting monomer. The preferred sequence for the grafting reactionincludes melting the propylene-based polymer, adding and dispersing thegrafting monomer, introducing the peroxide and venting the unreactedmonomer and by-products resulting from the peroxide decomposition. Othersequences can include feeding the monomers and the peroxidepre-dissolved in a solvent.

Illustrative peroxide initiator include but are not limited to: diacylperoxides such as benzoyl peroxide; peroxyesters such astert-butylperoxy benzoate, tert-butylperoxy acetate,OO-tert-butyl-O-(2-ethylhexyl)monoperoxy carbonate; peroxyketals such asn-butyl-4,4-di-(tert-butyl peroxy) valerate; and dialkyl peroxides suchas 1,1-bis(tertbutylperoxy) cyclohexane,1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane,2,2-bis(tert-butylperoxy)butane, dicumylperoxide,tert-butylcumylperoxide, Di-(2-tert-butylperoxy-isopropyl-(2))benzene,di-tert-butylperoxide (DTBP),2,5-dimethyl-2,5-di(tert-butylperoxy)hexane,2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne, 3,3,5,7,7-pentamethyl1,2,4-trioxepane; and the like.

Polyolefinic Thermoplastic Resin

The term “polyolefinic thermoplastic resin” as used herein refers to anymaterial that is not a “rubber” and that is a polymer or polymer blendhaving a melting point of 70° C. or more and considered by personsskilled in the art as being thermoplastic in nature, e.g., a polymerthat softens when exposed to heat and returns to its original conditionwhen cooled to room temperature. The polyolefinic thermoplastic resincan contain one or more polyolefins, including polyolefin homopolymersand polyolefin copolymers. Except as stated otherwise, the term“copolymer” means a polymer derived from two or more monomers (includingterpolymers, tetrapolymers, etc.), and the term “polymer” refers to anycarbon-containing compound having repeat units from one or moredifferent monomers.

Illustrative polyolefins can be prepared from mono-olefin monomersincluding, but are not limited to, monomers having 2 to 7 carbon atoms,such as ethylene, propylene, 1-butene, isobutylene, 1-pentene, 1-hexene,1-octene, 3-methyl-1-pentene, 4-methyl-1-pentene, 5-methyl-1-hexene,mixtures thereof and copolymers thereof with (meth)acrylates and/orvinyl acetates. Preferably, the polyolefinic thermoplastic resincomponent is unvulcanized or non crosslinked.

In one or more embodiments, the polyolefinic thermoplastic resincontains polypropylene. The term “polypropylene” as used herein broadlymeans any polymer that is considered a “polypropylene” by personsskilled in the art (as reflected in at least one patent or publication),and includes homo, impact, and random polymers of propylene. Preferably,the polypropylene used in the compositions described herein has amelting point above 110° C., includes at least 90 wt % propylene units,and contains isotactic sequences of those units. The polypropylene canalso include atactic sequences or s syndiotactic sequences, or both. Thepolypropylene can also include essentially syndiotactic sequences suchthat the melting point of the polypropylene is above 110° C. Thepolypropylene can either derive exclusively from propylene monomers(i.e., having only propylene units) or derive from mainly propylene(more than 80% propylene) with the remainder derived from olefins,particularly ethylene, and/or C₄-C₁₀ alpha-olefins. As noted elsewhereherein, certain polypropylenes have a high MFR (e.g., from a low of 10,or 15, or 20 g/10 min to a high of 25 to 30 g/10 min. Others have alower MFR, e.g., “fractional” polypropylenes which have an MFR less than1.0. Those with high MFR can be preferred for ease of processing orcompounding.

In one or more embodiments, the polyolefinic thermoplastic resin is orincludes isotactic polypropylene. Preferably, the polyolefinicthermoplastic resin contains one or more crystalline propylenehomopolymers or copolymers of propylene having a melting temperaturegreater than 105° C. as measured by DSC. Preferred copolymers ofpropylene include, but are not limited to, terpolymers of propylene,impact copolymers of propylene, random polypropylene and mixturesthereof. Preferred comonomers have 2 carbon atoms, or from 4 to 12carbon atoms. Preferably, the comonomer is ethylene. Such polyolefinicthermoplastic resin and methods for making the same are described inU.S. Pat. No. 6,342,565.

The term “random polypropylene” as used herein broadly means a copolymerof propylene having up to 9 wt %, preferably 2 wt % to 8 wt % of analpha olefin comonomer. Preferred alpha olefin comonomers have 2 carbonatoms, or from 4 to 12 carbon atoms. Preferably, the alpha olefincomonomer is ethylene.

In one or more embodiments, the random polypropylene has a 1% secantmodulus of about 100 kPsi to about 200 kPsi, as measured according toASTM D790A. In one or more embodiments, the 1% secant modulus can be 140kPsi to 170 kpsi, as measured according to ASTM D790A. In one or moreembodiments, the 1% secant modulus can be 140 kpsi to 160 kPsi, asmeasured according to ASTM D790A. In one or more embodiments, the 1%secant modulus can range from a low of about 100, 110, or 125 kPsi to ahigh of about 145, 160, or 175 kPsi, as measured according to ASTMD790A.

In one or more embodiments, the random polypropylene can have a densityof about 0.85 to about 0.95 g/cc, as measured by ASTM D792. In one ormore embodiments, the random polypropylene can have a density of about0.89 g/cc to 0.92 g/cc, as measured by ASTM D792. In one or moreembodiments, the density can range from a low of about 0.85, 0.87, or0.89 g/cc to a high of about 0.90, 0.91, 0.92 g/cc, as measured by ASTMD792

Secondary Elastomeric Component

The elastomeric composition can optionally include one or more secondaryelastomeric components. In at least one specific embodiment, thesecondary elastomeric component can be or include one or moreethylene-propylene copolymers (EP). Preferably, the ethylene-propylenepolymer (EP) is non-crystalline, e.g., atactic or amorphous, but incertain embodiments the EP may be crystalline (including“semi-crystalline”). The crystallinity of the EP is preferably derivedfrom the ethylene, and a number of published methods, procedures andtechniques are available for evaluating whether the crystallinity of aparticular material is derived from ethylene. The crystallinity of theEP can be distinguished from the crystallinity of the propylene-basedpolymer by removing the EP from the composition and then measuring thecrystallinity of the residual propylene-based polymer. Suchcrystallinity measured is usually calibrated using the crystallinity ofpolyethylene and related to the comonomer content. The percentcrystallinity in such cases is measured as a percentage of polyethylenecrystallinity and thus the origin of the crystallinity from ethylene isestablished.

In one or more embodiments, the EP can include one or more optionalpolyenes, including particularly a diene; thus, the EP can be anethylene-propylene-diene (commonly called “EPDM”). The optional polyeneis considered to be any hydrocarbon structure having at least twounsaturated bonds wherein at least one of the unsaturated bonds isreadily incorporated into a polymer. The second bond may partially takepart in polymerization to form long chain branches but preferablyprovides at least some unsaturated bonds suitable for subsequent curingor vulcanization in post polymerization processes. Examples of EP orEPDM copolymers include V722, V3708P, MDV 91-9, V878 that are availableunder the trade name Vistalon from ExxonMobil Chemicals. Severalcommercial EPDM are available from DOW under the trade Nordel IP and MGgrades.). Certain rubber components (e.g., EPDMs, such as Vistalon 3666)include additive oil that is preblended before the rubber component iscombined with the thermoplastic. The type of additive oil utilized willbe that customarily used in conjunction with a particular rubbercomponent.

Examples of the optional polyene include, but are not limited to,butadiene, pentadiene, hexadiene (e.g., 1,4-hexadiene), heptadiene(e.g., 1,6-heptadiene), octadiene (e.g., 1,7-octadiene), nonadiene(e.g., 1,8-nonadiene), decadiene (e.g., 1,9-decadiene), undecadiene(e.g., 1,10-undecadiene), dodecadiene (e.g., 1,11-dodecadiene),tridecadiene (e.g., 1,12-tridecadiene), tetradecadiene (e.g.,1,13-tetradecadiene), pentadecadiene, hexadecadiene, heptadecadiene,octadecadiene, nonadecadiene, icosadiene, heneicosadiene, docosadiene,tricosadiene, tetracosadiene, pentacosadiene, hexacosadiene,heptacosadiene, octacosadiene, nonacosadiene, triacontadiene, andpolybutadienes having a molecular weight (Mw) of less than 1000 g/mol.Examples of straight chain acyclic dienes include, but are not limitedto 1,4-hexadiene and 1,6-octadiene. Examples of branched chain acyclicdienes include, but are not limited to 5-methyl-1,4-hexadiene,3,7-dimethyl-1,6-octadiene, and 3,7-dimethyl-1,7-octadiene. Examples ofsingle ring alicyclic dienes include, but are not limited to1,4-cyclohexadiene, 1,5-cyclooctadiene, and 1,7-cyclododecadiene.Examples of multi-ring alicyclic fused and bridged ring dienes include,but are not limited to tetrahydroindene; norbornadiene;methyltetrahydroindene; dicyclopentadiene;bicyclo(2.2.1)hepta-2,5-diene; and alkenyl-, alkylidene-, cycloalkenyl-,and cylcoalkyliene norbornenes [including, e.g.,5-methylene-2-norbornene, 5-ethylidene-2-norbornene,5-propenyl-2-norbornene, 5-isopropylidene-2-norbornene,5-(4-cyclopentenyl)-2-norbornene, 5-cyclohexylidene-2-norbornene, and5-vinyl-2-norbornene]. Examples of cycloalkenyl-substituted alkenesinclude, but are not limited to vinyl cyclohexene, allyl cyclohexene,vinylcyclooctene, 4-vinylcyclohexene, allyl cyclodecene,vinylcyclododecene, and tetracyclododecadiene.

In another embodiment, the secondary elastomeric component can include,but is not limited to, styrene/butadiene rubber (SBR), styrene/isoprenerubber (SIR), styrene/isoprene/butadiene rubber (SIBR),styrene-butadiene-styrene block copolymer (SBS), hydrogenatedstyrene-butadiene-styrene block copolymer (SEBS), hydrogenatedstyrene-butadiene block copolymer (SEB), styrene-isoprene-styrene blockcopolymer (SIS), styrene-isoprene block copolymer (SI), hydrogenatedstyrene-isoprene block copolymer (SEP), hydrogenatedstyrene-isoprene-styrene block copolymer (SEPS),styrene-ethylene/butylene-ethylene block copolymer (SEBE),styrene-ethylene-styrene block copolymer (SES),ethylene-ethylene/butylene block copolymer (EEB),ethylene-ethylene/butylene/styrene block copolymer (hydrogenated BR-SBRblock copolymer), styrene-ethylene/butylene-ethylene block copolymer(SEBE), ethylene-ethylene/butylene-ethylene block copolymer (EEBE),polyisoprene rubber, polybutadiene rubber, isoprene butadiene rubber(IBR), polysulfide, nitrile rubber, propylene oxide polymers,star-branched butyl rubber and halogenated star-branched butyl rubber,brominated butyl rubber, chlorinated butyl rubber, star-branchedpolyisobutylene rubber, star-branched brominated butyl(polyisobutylene/isoprene copolymer) rubber;poly(isobutylene-co-alkylstyrene), preferably isobutylene/methylstyrenecopolymers such as isobutylene/meta-bromomethylstyrene,isobutylene/bromomethylstyrene, isobutylene/chloromethylstyrene,halogenated isobutylene cyclopentadiene, andisobutylene/chloromethylstyrene and mixtures thereof. Preferredsecondary elastomeric components include hydrogenatedstyrene-butadiene-styrene block copolymer (SEBS), and hydrogenatedstyrene-isoprene-styrene block copolymer (SEPS).

The secondary elastomeric component can also be or include naturalrubber. Natural rubbers are described in detail by Subramaniam in RUBBERTECHNOLOGY 179-208 (1995). Suitable natural rubbers can be selected fromthe group consisting of Malaysian rubber such as SMR CV, SMR 5, SMR 10,SMR 20, and SMR 50 and mixtures thereof, wherein the natural rubbershave a Mooney viscosity at 100° C. (ML 1+4) of from 30 to 120, morepreferably from 40 to 65. The Mooney viscosity test referred to hereinis in accordance with ASTM D-1646.

The secondary elastomeric component can also be or include one or moresynthetic rubbers. One suitable commercially available synthetic rubberinclude NATSYN™ (Goodyear Chemical Company), and BUDENE™ 1207 or BR 1207(Goodyear Chemical Company). A desirable rubber is highcis-polybutadiene (cis-BR). By “cis-polybutadiene” or “highcis-polybutadiene”, it is meant that 1,4-cis polybutadiene is used,wherein the amount of cis component is at least 95%. An example of highcis-polybutadiene commercial products used in the composition BUDENE™1207.

The secondary elastomeric component can be present in a range from up to50 phr in one embodiment, from up to 40 phr in another embodiment, andfrom up to 30 phr in yet another embodiment. In one or more embodiments,the amount of the secondary rubber component can range from a low ofabout 1, 7, or 20 phr to a high of about 25, 35, or 50 phr.

Additive Oil

The elastomeric composition can optionally include one or more additiveoils. The term “additive oil” includes both “process oils” and “extenderoils.” For example, “additive oil” may include hydrocarbon oils andplasticizers, such as organic esters and synthetic plasticizers. Manyadditive oils are derived from petroleum fractions, and have particularASTM designations depending on whether they fall into the class ofparaffinic, naphthenic, or aromatic oils. Other types of additive oilsinclude mineral oil, alpha olefinic synthetic oils, such as liquidpolybutylene, e.g., products sold under the trademark Parapol®. Additiveoils other than petroleum based oils can also be used, such as oilsderived from coal tar and pine tar, as well as synthetic oils, e.g.,polyolefin materials (e.g., SpectaSyn™ and Elevast™, both supplied byExxonMobil Chemical Company.

The ordinarily skilled chemist will recognize which type of oil shouldbe used with a particular rubber, and also be able to determine theamount (quantity) of oil. The additive oil can be present in amountsfrom about 5 to about 300 parts by weight per 100 parts by weight of theblend of the rubber and thermoplastic components. The amount of additiveoil may also be expressed as from about 30 to 250 parts, and moredesirably from about 70 to 200 parts by weight per 100 parts by weightof the rubber component. Alternatively, the quantity of additive oil canbe based on the total rubber content, and defined as the ratio, byweight, of additive oil to total rubber and that amount may in certaincases be the combined amount of process oil and extender oil. The ratiomay range, for example, from about 0 to about 4.0/l. Other ranges,having any of the following lower and upper limits, may also beutilized: a lower limit of 0.1/l, or 0.6/l, or 0.8/l, or 1.0/l, or1.2/l, or 1.5/l, or 1.8/l, or 2.0/l, or 2.5/l; and an upper limit (whichmay be combined with any of the foregoing lower limits) of 4.0/l, or3.8/l, or 3.5/l, or 3.2/l, or 3.0/l, or 2.8/l. Larger amounts ofadditive oil can be used, although the deficit is often reduced physicalstrength of the composition, or oil weeping, or both.

Polybutene oils are preferred. Preferable polybutene oils have an Mn ofless than 15,000, and include homopolymer or copolymer of olefin derivedunits having from 3 to 8 carbon atoms and more preferably from 4 to 6carbon atoms. In one or more embodiments, the polybutene is ahomopolymer or copolymer of a C₄ raffinate. An embodiment of preferredlow molecular weight polymers termed “polybutene” polymers is describedin, for example, SYNTHETIC LUBRICANTS AND HIGH-PERFORMANCE FUNCTIONALFLUIDS 357-392 (Leslie R. Rudnick & Ronald L. Shubkin, ed., MarcelDekker 1999) (hereinafter “polybutene processing oil” or “polybutene”).

In one or more embodiments, the polybutene processing oil is a copolymerhaving at least isobutylene derived units, and optionally 1-butenederived units, and/or 2-butene derived units. In one embodiment, thepolybutene is a homopolymer if isobutylene, or a copolymer ofisobutylene and 1-butene or 2-butene, or a terpolymer of isobutylene and1-butene and 2-butene, wherein the isobutylene derived units are from 40to 100 wt % of the copolymer, the 1-butene derived units are from 0 to40 wt % of the copolymer, and the 2-butene derived units are from 0 to40 wt % of the copolymer. In another embodiment, the polybutene is acopolymer or terpolymer wherein the isobutylene derived units are from40 to 99 wt % of the copolymer, the 1-butene derived units are from 2 to40 wt % of the copolymer, and the 2-butene derived units are from 0 to30 wt % of the copolymer. In yet another embodiment, the polybutene is aterpolymer of the three units, wherein the isobutylene derived units arefrom 40 to 96 wt % of the copolymer, the 1-butene derived units are from2 to 40 wt % of the copolymer, and the 2-butene derived units are from 2to 20 wt % of the copolymer. In yet another embodiment, the polybuteneis a homopolymer or copolymer of isobutylene and 1-butene, wherein theisobutylene derived units are from 65 to 100 wt % of the homopolymer orcopolymer, and the 1-butene derived units are from 0 to 35 wt % of thecopolymer. Commercial examples of a suitable processing oil includes thePARAPOL™ Series of processing oils or Polybutene grades or Indopol™ fromSoltex Synthetic Oils and Lubricants or from BP/Innovene.

The processing oil or oils can be present at 1 to 60 phr in oneembodiment, and from 2 to 40 phr in another embodiment, from 4 to 35 phrin another embodiment, and from 5 to 30 phr in yet another embodiment.

Co-Agents

The elastomeric composition can optionally include one or moreco-agents. Suitable co-agents can include liquid and metallicmultifunctional acrylates and methacrylates, functionalizedpolybutadiene resins, functionalized cyanurate, and allyl isocyanurate.More particularly, suitable co-agents can include, but are not limitedto polyfunctional vinyl or allyl compounds such as, for example,triallyl cyanurate, triallyl isocyanurate, pentaerthritoltetramethacrylate, ethylene glycol dimethacrylate, diallyl maleate,dipropargyl maleate, dipropargyl monoallyl cyanurate,azobisisobutyronitrile and the like, and combinations thereof.Commercially available co-agents can be purchased from Sartomer.

In one or more embodiments, the elastomeric composition contains atleast 0.1 wt % of co-agent based on the total weight of blend. In one ormore embodiments, the amount of co-agent(s) can range from about 0.1 wt% to about 15 wt %, based on the total weight of blend. In one or moreembodiments, the amount of co-agent(s) can range from a low of about 0.1wt %, 1.5 wt % or 3.0 wt % to a high of about 4.0 wt %, 7.0 wt %, or 15wt %, based on the total weight of blend. In one or more embodiments,the amount of co-agent(s) can range from a low of about 2.0 wt %, 3.0 wt% or 5.0 wt % to a high of about 7.0 wt %, 9.5 wt %, or 12.5 wt %, basedon the total weight of blend. In one or more embodiments, the amount ofco-agent(s) is about 3 wt %, based on the total weight of blend.

Antioxidants

The elastomeric composition can optionally include one or moreanti-oxidants. Suitable anti-oxidants can include hindered phenols,phosphites, hindered amines, Irgafos 168, Irganox 1010, Irganox 3790,Irganox B225, Irganxo 1035, Irgafos 126, Irgastab 410, Chimassorb 944,etc. made by Ciba Geigy Corp. These may be added to the elastomericcomposition to protect against degradation during shaping or fabricationoperation and/or to better control the extent of chain degradation.

In one or more embodiments, the elastomeric composition contains atleast 0.1 wt % of antioxidant, based on the total weight of blend. Inone or more embodiments, the amount of antioxidant(s) can range fromabout 0.1 wt % to about 5 wt %, based on the total weight of blend. Inone or more embodiments, the amount of antioxidant(s) can range from alow of about 0.1 wt %, 0.2 wt % or 0.3 wt % to a high of about 1 wt %,2.5 wt %, or 5 wt %, based on the total weight of blend. In one or moreembodiments, the amount of antioxidant(s) is about 0.1 wt %, based onthe total weight of blend. In one or more embodiments, the amount ofantioxidant(s) is about 0.2 wt %, based on the total weight of blend. Inone or more embodiments, the amount of antioxidant(s) is about 0.3 wt %,based on the total weight of blend. In one or more embodiments, theamount of antioxidant(s) is about 0.4 wt %, based on the total weight ofblend. In one or more embodiments, the amount of antioxidant(s) is about0.5 wt %, based on the total weight of blend.

Blending and Additives

In one or more embodiments, the individual materials and components,such as the propylene-based polymer and optionally the one or morepolyolefinic thermoplastic resins, secondary elastomeric component,additive oil, co-agents, and anti-oxidants can be blended by melt-mixingto form a blend. Examples of machinery capable of generating the shearand mixing include extruders with kneaders or mixing elements with oneor more mixing tips or flights, extruders with one or more screws,extruders of co or counter rotating type, Banbury mixer, FarrellContinuous mixer, and the Buss Kneader. The type and intensity ofmixing, temperature, and residence time required can be achieved by thechoice of one of the above machines in combination with the selection ofkneading or mixing elements, screw design, and screw speed (<3000 RPM).

In one or more embodiments, the blend can include the propylene-basedpolymer in an amount ranging from a low of about 60, 70 or 75 wt % to ahigh of about 80, 90, or 95 wt %. In one or more embodiments, the blendcan include the one or more polyolefinic thermoplastic components in anamount ranging from a low of about 5, 10 or 20 wt % to a high of about25, 30, or 75 wt %. In one or more embodiments, the blend can includethe secondary elastomeric component in an amount ranging from a low ofabout 5, 10 or 15 wt % to a high of about 20, 35, or 50 wt %.

In one or more embodiments, the co-agents, antioxidants, and/or otheradditives can be introduced at the same time as the other polymercomponents or later downstream in case of using an extruder or Busskneader or only later in time. In addition to the co-agents andantioxidants described, other additives can include antiblocking agents,antistatic agents, ultraviolet stabilizers, foaming agents, andprocessing aids. The additives can be added to the blend in pure form orin master batches.

Cured Products

The formed article (e.g., extruded article) can be a fiber, yarn orfilm, and is at least partially crosslinked or cured. Preferably, theformed article is at least partially crosslinked or cured so that thearticle becomes heat-resistant. As used herein, the term“heat-resistant” refers to the ability of a polymer composition or anarticle formed from a polymer composition to pass the high temperatureheat-setting and dyeing tests described herein. As used herein, theterms “cured,” “crosslinked,” “at least partially cured,” and “at leastpartially crosslinked” refer to a composition having at least 2 wt %insolubles based on the total weight of the composition. In one or moreembodiments, the compositions described herein can be cured to a degreeso as to provide at least 3 wt %, or at least 5 wt %, or at least 10 wt%, or at least 20 wt %, or at least 35 wt %, or at least 45 wt %, or atleast 65 wt %, or at least 75 wt %, or at least 85 wt %, or less than 95wt % insolubles using Xylene as the solvent by Soxhlet extraction.

In a particular embodiment, the crosslinking is accomplished by electronbeam or simply “ebeam” after shaping or extruding the article. Suitableebeam equipment is available from E-BEAM Services, Inc. In a particularembodiment, electrons are employed at a dosage of about 100 kGy or lessin multiple exposures. The source can be any electron beam generatoroperating in a range of about 150 Kev to about 12 mega-electron volts(MeV) with a power output capable of supplying the desired dosage. Theelectron voltage can be adjusted to appropriate levels which may be, forexample, 100,000; 300,000; 1,000,000; 2,000,000; 3,000,000; 6,000,000. Awide range of apparatus for irradiating polymers and polymeric articlesis available.

Effective irradiation is generally carried out at a dosage between about10 kGy (Kilogray) to about 350 kGy, preferably from about 20 to about350 kGy, or from about 30 to about 250 kGy, or from about 40 to about200 kGy. In a particular aspect of this embodiment, the irradiation iscarried out at room temperature.

In another embodiment, crosslinking can be accomplished by exposure toone or more chemical agents in addition to the e-beam cure. Illustrativechemical agents include but are not limited to peroxides and other freeradical generating agents, sulfur compounds, phenolic resins, andsilicon hydrides. In a particular aspect of this embodiment, thecrosslinking agent is either a fluid or is converted to a fluid suchthat it can be applied uniformly to the article. Fluid crosslinkingagents include those compounds which are gases (e.g., sulfurdichloride), liquids (e.g., Trigonox C, available from Akzo Nobel),solutions (e.g., dicumyl peroxide in acetone, or suspensions thereof(e.g., a suspension or emulsion of dicumyl peroxide in water, or redoxsystems based on peroxides).

Illustrative peroxides include, but are not limited to dicumyl peroxide,di-tert-butyl peroxide, t-butyl perbenzoate, benzoyl peroxide, cumenehydroperoxide, t-butyl peroctoate, methyl ethyl ketone peroxide,2,5-dimethyl-2,5-di(t-butyl peroxy)hexane, lauryl peroxide, tert-butylperacetate. When used, peroxide curatives are generally selected fromorganic peroxides. Examples of organic peroxides include, but are notlimited to, di-tert-butyl peroxide, dicumyl peroxide, t-butylcumylperoxide, α,α-bis(tert-butylperoxy) diisopropyl benzene, 2,5 dimethyl2,5-di(t-butylperoxy)hexane, 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane, -butyl-4,4-bis(tert-butylperoxy) valerate, benzoylperoxide, lauroyl peroxide, dilauroyl peroxide,2,5-dimethyl-2,5-di(tert-butylperoxy) hexene-3, and mixtures thereof.Also, diaryl peroxides, ketone peroxides, peroxydicarbonates,peroxyesters, dialkyl peroxides, hydroperoxides, peroxyketals andmixtures thereof may be used.

In one or more embodiments, the crosslinking can be carried out usinghydrosilylation techniques.

In one or more embodiments, the crosslinking can be carried out under aninert or oxygen-limited atmosphere. Suitable atmospheres can be providedby the use of helium, argon, nitrogen, carbon dioxide, xenon and/or avacuum.

Crosslinking either by chemical agents or by irradiation can be promotedwith a crosslinking catalyst, such as organic bases, carboxylic acids,and organometallic compounds including organic titanates and complexesor carboxylates of lead, cobalt, iron, nickel, zinc, and tin (such asdibutyltindilaurate, dioctyltinmaleate, dibutyltindiacetate,dibutyltindioctoate, stannous acetate, stannous octoate, leadnaphthenate, zinc caprylate, cobalt naphthenate, and the like).

EXAMPLES

The foregoing discussion can be further described with reference to thefollowing non-limiting examples. Elastomeric compositions containing atleast one propylene-based copolymer in accordance with one or moreembodiments described were prepared.

Tables 1 summarize the formulations of the compositions. Eachcomposition was prepared in a Brabender thermoplastic compounder. Thepellets of the copolymer with the thermoplastic component were chargedinto the Brabender in the presence of a nitrogen blanket along with theantioxidants at a melt temperature of 170° C. for 3 minutes. Thetemperature was then lowered to 140° C. and the co-agent was added andmixed for about 2 minutes at 40 rpm to obtain a homogenous blend. Theblends were then molded into 2 mm thick pads with 12 cm×14 cm dimensionson a compression molding press.

TABLE 1 Formulations in weight percent PP PB Rheine JSR PCP- PCP- PP PP9632 0110 Sartomer Irganox Irganox Irgafos Irgafos Irgastab Chemie NTXMDV RB8 Blend 01 02 5341 9122 E1 M TAC 350 B225 1035 126 168 FS 410 TAIC10316 91-9 40 1 95 5 2 95 5 3 92 5 3 4 90 5 5 5 88 5 7 6 90 5 5 7 92 5 38 94.8 5 0.2 9 94.8 5 0.1 0.1 10 94.8 5 0.2 11 94.8 5 0.2 12 94.8 5 0.213 91.8 5 3 0.2 14 89.8 5 5 0.2 15 91.8 5 3 0.2 16 91.8 5 3 0.2 17 91.85 3 0.2 18 89.8 5 5 0.2 19 91.8 5 3 0.2 20 91.8 5 3 0.2 21 91.8 5 3 0.222 91.8 5 3 0.2 23 91.8 5 3 0.2 24 91.8 5 3 0.2 25 91.8 5 3 0.2 26 86.810 3 0.2 27 92.2 4.8 3.0 28 92.2 4.8 3.0 29 85.5 4.5 10.0 30 82.7 4.3 310.0 31 90.0 10.0 32 85.5 4.5 10.0 33 95.0 5 34 92.2 4.8 3

PCP-01 is a metallocene catalyzed propylene/ethylene copolymer having 16wt % of ethylene and 2.5 wt % ENB. The melting point was less than 50°C. The Mooney viscosity (ML (1+4) at 125° C.) was 17.5 as measuredaccording to a method based on ASTM D 1646. The MFR (2.16 kg at 230° C.)was 4 g/10 min.

PCP-02 is a metallocene catalyzed propylene/ethylene copolymer having 16wt % of ethylene and 2.4 wt % ENB. The melting point was less than 100°C. The Mooney viscosity (ML (1+4) at 125° C.) was 18.3 as measuredaccording to a method based on ASTM D 1646. The MFR (2.16 kg at 230° C.)was 3.7 g/10 min.

PP 5341 is a 0.8 MFR (230° C., 2.16 kg) isotactic polypropylene (iPP)that is commercially available from ExxonMobil Chemical Company.

RCP 9632E1 is a random copolymer containing 2-3 wt % of ethylene derivedunits, the balance is propylene. The RCP 9632E1 has a MFR (2.16 kg at230° C.) of 2.5 g/10 min and a density of 0.9 g/cm³. The 1% secantflexural modulus is 155 kPsi, as measured by ASTM D790A. RCP 9632E1 iscommercially available from ExxonMobil Chemical Company.

RCP 9122 is a random copolymer containing 2-3 wt % of ethylene derivedunits, the balance is propylene. The RCP 9122 has a MFR (2.16 kg at 230°C.) of 2.1 g/10 min and a density of 0.9 g/cm³. The 1% secant flexuralmodulus is 140 kPsi, as measured by ASTM D790A.RCP 9122 is commerciallyavailable from ExxonMobil Chemical Company.

TAC is Tri-Allyl Cyanurate.

Sartomer 350 is a trimethylolpropane trimethacrylate co-agent that iscommercially available from Sartomer Company, Inc. located in Exton, Pa.

Irgastab FS 410 and Irgafos 168 are antioxidants that are commerciallyavailable from Ciba Specialty Chemicals.

TAIC is triallylisocyanurate, b.p. 149-152° C./4 mm Hg (500 ppmt-butylhydroquinone as inhibitor) (Rhein Chemie).

NTX 10316 is an allylurethane oligomer (Sartomer Co.).

RB840 is syndiotatic 1,2-Polybutadiene m.p. 130° C., MFR (150° C., 21.2N): 8.0 (JSR America)

PB0110M is isotactic poly(l-butene) m.p. 125° C., MFR (230° C., 2.16kg): 1.0 (Basell Polyolefins).

MDV 91-9 is an EP copolymer (ExxonMobil Chemical) with about 60 wt %ethylene and has a Mooney viscosity (ML (1+4) at 125° C.) about 19 andnarrow molecular weight distribution.

The plaques were then crosslinked using electron beam radiation forvarious periods of time at room temperature. The selected dosages were50, 75,100 and 150 kGy. The MFR of the blends were tested at 230° C.using 2.16 kg load.

Physical properties of the plaques before and after curing wereevaluated. The test methods included ISO 878 for Hardness, ISO 37 forultimate tensile strength (UTS) and ultimate elongation (UE), and ASTMD412 standard guidelines. The tension set of the blends were testedaccording to ASTM D412 at room temperature and 70 C. For roomtemperature and 70 C testing for tension set the sample was aged at thetest temperature for 30 minutes under 50% tension on Jig and annealed atroom temperature for 30 minute after removing from the Jig. A xyleneSoxhlet solvent extraction test was conducted according to ASTM D5492 onthe cured samples using a Soxhlet extractor (extraction time=12 hrs) tounderstand the level of crosslinked material after e-beam curing.Results are expressed as: percent Xylene insoluble =weight afterextraction/weight before extraction*100. The amount of insoluble gelbefore e-beam radiation crosslinking was practically undetectable bythis method.

Table 2 summarizes the physical properties of the plaques prior toe-beam cure. Table 3 summarizes the e-beam dosage and physicalproperties of the plaques after curing.

TABLE 2 Mechanical properties of the uncured plaques. Hardness, MFRStress at Peak Peak 100% Tension Tension Shore A, (230° C., break,Strain at stress, Elongation, Mod. Set, (%) at Set, (%) at Blend 15s.2.16 kg) MPa Break, % (MPa) (%) (MPa) 23° C. 70° C. 1 57.0 4.2 — nobreak 11.1 — 1.9 5% 51% 2 57.4 4.0 — no break 10.9 — 1.9 5% 49% 3 53.25.3 — no break 9.7 — 1.7 6% 49% 4 52.8 6.2 — no break 9.6 — 1.7 5% 49% 552.8 8.9 — no break 9.1 — 1.7 6% 49% 6 52.8 0.83 — no break 10.5 — 1.68% 45% 7 58.4 0.4 — NA 11.0 840 1.7 NA NA 8 55.2 3.9 10.1 780 — 1.9 6%49% 9 55.6 3.8 — no break 10.8 — 1.8 4% 48% 10 55.6 4.5 — no break 10.7— 1.8 6% 49% 11 57 3.9 10.5 821 10.6 820 1.6 NA NA 12 58 3.7 — no break10.9 — 1.8 6% 49% 13 56 NA — — 10.3 836 1.6 NA NA 14 54 6.6 — no break9.1 — 1.6 6% 49% 15 55.2 6.3 — — 8.7 840 1.6 — — 16 57.4 2.2 — — 9.6 8401.7 — — 17 53.4 5.3 — — 8.6 840 1.5 — — 18 54.2 6.1 — no break 9.2 — 1.76% 47% 19 56.4 6.1 — — 8.7 840 1.6 — — 20 54.2 4.7 — — 8.6 840 1.5 — —21 54 4.27  9.7 843 10.2 840 1.5 — — 22 57.6 4.76 — — 10.9 800 1.8 — —23 57.4 3 — — 9.7 820 1.7 — — 24 55 4.31 10.3 841 10.3 820 1.6 — — 2559.6 4.64 — — 11.3 840 1.8 — — 26 63 4.58 11.5 838 13.2 820 2.0 — — 2755 — 15.7 920 — — 2.1 2.5 broke 28 63 — 13.2 870 — — 1.8 1.3 46.3 29 64— 13.1 860 — — 1.7 2.5 43.8 30 63 — 13.9 910 — — 1.7 2.5 43.8 31 65 —11.8 860 — — 1.9 2.5 53.8 32 68 — 12.4 800 — — 2.1 2.5 46.3 33 64 — 12.4810 — — 1.8 2.5 broke 34 58 — 15.2 870 — — 1.7 2.5 broke

TABLE 3 Mechanical properties of the cured plaques. Tension TensionXylene e-beam Stress at Peak Peak 100% Set, TS Set, TS Extraction dose,break, Strain at stress, Elongation Mod. (%), (%), (%) Blend kGy MPaBreak, % (MPa) (%) (MPa) 23° C. 70° C. insolubles 1 50 8.4 706 — — 1.95% 29% 67 2 50 9.6 733 — — 1.9 4% 29% 73 3 50 — no break 9.9 — 1.7 4%38% 39 4 50 — no break 9.4 — 1.6 4% 39% 39 5 50 — no break 9.2 — 1.5 9%39% 40 6 50 — 525 9.1 — 2.2 5% 19% 83 7 50 9.6 617 — — 2.2 5.5 25.3 70.18 50 8.7 769 — — 1.8 5% 35% 50 9 50 10.9 790 — — 1.8 4% 32% 63 10 5011.3 785 — — 1.8 5% 31% 66 11 50 11.5 792 11.4 780 2.0 4 27 73 12 5010.4 781 — — 1.8 5% 30% 66 13 60 10.1 635 10.1 640 2.0 NA NA NA 14 509.1 868 — — 1.5 4% 39% 47 15 50 — — 9.8 840 1.8 6.0 40.0 14.4 16 50 11.3658 — — 2.1 4.5 23.5 72.6 17 50 — — 9.5 840 1.6 4.8 39.3 19.5 18 50 — nobreak 10.2 1.6 5% 40% 48 19 50 — — 9.6 840 1.8 6.0 39.0 18.5 20 50 11.6614 — — 1.9 5.3 21.5 82.3 21 50 11.8 700 11.8 640 2.1 4 20 83 22 50 12.8680 12.8 660 2.2 3 18 83 23 50 11.8 659 — — 2.1 5.3 24.3 68 24 50 12.6717 12.7 700 2.2 3 22 84 25 50 13 712 13 660 2.3 4 20 86 26 50 12.5 66412.5 600 2.6 3 23 86 27 50 10.3 670 — — 2.2 2.5 25 68 28 50 12.8 800 — —2.2 2.5 27.5 71 29 50 12.8 780 — — 2.0 2.5 27.5 71 30 50 11.9 660 — —2.2 2.5 20 84 31 50 13.3 760 — — 2.2 2.5 25 73 32 50 12.7 710 — — 2.32.5 26.3 79 33 50 13.6 780 — — 1.9 2.5 21.3 76 34 50 13.7 650 — — 2.02.5 12.5 86

It was surprisingly found that the blends containing Irgastab FS410,TAC, Sartomer 350 and Irganox 168 showed increased tensile propertiesafter e-beam (50 kGy) crosslinking, where the blends containing noco-agents or antioxidants showed a decrease in tensile properties aftere-beaming. It is also surprisingly noted that blends containing theco-agent Sartomer 350 or TAC with antioxidants Irganox 168 or IrgastabFS 410 increased tensile properties after e-beam (50 kGy) crosslinking.Such addition of co-agents and/or antioxidants would not have beenthought to overcome the reduction in tensile properties resulting fromthe e-beam breakdown, chain scission of the propylene copolymerbackbone.

Fiber properties of selected blends were also evaluated. Blends 1, 11,21, and 24 were selected based on their excellent balance of physicalproperties. To test the physical properties of the fibers, the selectedblends were spun into fiber using a partially oriented yarn line havinga L:D ratio of 24:1. The spinnerette had 72 holes. Each hole had adiameter of 0.6 mm. The output of the line ranged from about 0.4 to 2gram/hole/min, with a Godet speed close to 5,000 m/min and a windingspeed of from 100 m/min to 3,000 m/min. The extruded fibers were cooledby quenched air having a temperature of about 45° F. to 55° F.

Table 4 summarizes the physical properties of both the cured and uncuredfibers. As shown below, the cured fibers exhibited excellentspinnability and fiber formation.

TABLE 4 Fiber Properties Winder Ebeam Count, speed, Melt dosage, den (72Tenacity, Xylene TS, % TS, % Blend m/min ghm T, F. megaRAD filaments)g/den Elong., % insoluble, % at 23 C. at 70 C. 1 300 0.6 519 0 1260 0.57195 4 21 1 300 0.6 519 5 1260 0.46 171 37 NA NA 1 400 0.6 519 0 13500.57 170 2.5 13 1 400 0.6 519 5 1350 NA NA 31 1 24 21 260 0.6 519 0 16500.36 157 5 20 21 260 0.6 519 5 1566 0.35 166 55 0.5 14 21 260 0.6 519 01583 0.31 161 0.5 22 21 260 0.6 519 6 1520 0.32 146 58 1 14 21 145 0.6519 0 2939 0.23 166 0.5 25 21 145 0.6 519 5 2849 0.22 158 60 0.5 20 21145 0.6 519 0 2887 0.25 176 0.5 22 21 145 0.6 519 6 2857 0.21 156 64 413 11 260 0.6 519 0 1416 0.42 170 0.5 19 11 260 0.6 519 4 1416 0.33 14344 3.5 35 11 260 0.6 519 0 1360 0.4 158 5 25 11 260 0.6 519 5 1068 0.3119 45 1 12.5 11 260 0.6 519 0 1030 0.49 102 2 25 11 260 0.6 519 6 10300.39 171 46 1 10 11 130 0.6 519 0 2690 0.68 143 2 24 11 130 0.6 519 52690 0.76 151 52 0.5 19 24 250 0.6 519 0 1260 0.32 122 5 17 24 250 0.6519 4 1260 NA NA 43 0.5 15 24 250 0.6 519 0 1180 0.33 146 3 18 24 2500.6 519 5 1280 0.43 167 58 2 10 24 250 0.6 519 0 1040 0.36 147 2 15 24250 0.6 519 6 1020 0.37 162 61 4 7 24 300 0.6 519 0 750 0.42 166 2.5 1024 300 0.6 519 5 800 0.53 103 57 7 5

Monolayer films from blends 1, 11, 21 and 24 were also prepared. Thefilms were made by compression molding, similar to the process used formaking the plaques. The thickness of each film was about 10 mil.

The results are shown below in Tables 5 and 6. Table 5 summarizes thephysical properties of the films before e-beam cure and Table 6summarizes the physical properties of the films after e-beam cure usinga dosage of 50 kGy.

TABLE 5 Film Properties before cure Blend 1 11 24 21 Stress at Break,psi 1437 1253 1910 1602 Elongation at break, (%) 1393 1298 1624 1530100% Mod, MPa 247 245 252 231 Energy at Break, in * lbf 12.6 11.2 19.615.3

TABLE 6 Film Properties after e-beam curing at 50 kGy dose Blend 1 11 2421 Stress at Break, psi 1724 1787 1916 1317 Elongation at break, (%)1457 1614 1423 1165 100% Mod, psi 267 255 277 262 Energy at Break, in *lbf 15.9 20.0 16.9 10.3 Xylene Extraction, % 53 56 62 67 insolubles

It was surprisingly found that the ebeam cured films maintained theirtensile strength after curing even at such high levels (i.e. >50%) ofcrosslinking as measured by the xylene extraction, percent insolubles.The opposite would have been expected considering the strengthproperties of cured films are usually sacrificed during crosslinking.

For purposes of convenience, various specific test procedures areidentified above for determining certain properties such as tensile set,percent elongation at break, Shore A Hardness, and toughness. However,when a person of ordinary skill reads this patent and wishes todetermine whether a composition or polymer has a particular propertyidentified in a claim, then any published or well-recognized method ortest procedure can be followed to determine that property, although thespecifically identified procedure is preferred. Each claim should beconstrued to cover the results of any of such procedures, even to theextent different procedures can yield different results or measurements.Thus, a person of ordinary skill in the art is to expect experimentalvariations in measured properties that are reflected in the claims. Allnumerical values can be considered to be “about” or “approximately” thestated value, in view of the nature of testing in general.

Certain embodiments and features have been described using a set ofnumerical upper limits and a set of numerical lower limits. It should beappreciated that ranges from any lower limit to any upper limit arecontemplated unless otherwise indicated. Certain lower limits, upperlimits and ranges appear in one or more claims below. All numericalvalues are “about” or “approximately” the indicated value, and take intoaccount experimental error and variations that would be expected by aperson having ordinary skill in the art.

To the extent a term used in a claim is not defined above, it should begiven the broadest definition persons in the pertinent art have giventhat term as reflected in at least one printed publication or issuedpatent. Furthermore, all patents, test procedures, and other documentscited in this application are fully incorporated by reference to theextent such disclosure is not inconsistent with this application and forall jurisdictions in which such incorporation is permitted.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

Having described the various aspects of the compositions herein,described in various numbered embodiments is:

-   1. A crosslinked elastomeric composition, comprising at least one    propylene-based polymer comprising propylene derived units and one    or more dienes, the propylene-based polymer having a triad tacticity    of from 50% to 99% and a heat of fusion of less than 80 J/g; at    least one component selected from the group consisting of    multifunctional acrylates, multifunctional methacrylates,    functionalized polybutadiene resins, functionalized cyanurate, and    allyl isocyanurate; at least one component comprising    trimethylolpropane trimethacrylate; one or more polyolefinic    thermoplastic components; and optionally one or more secondary    elastomeric components, wherein the crosslinked polypropylene has    great than 50% xylene insolubles as measured according to ASTM-D    5492.-   2. A method for making a crosslinked elastomeric article of numbered    embodiment 1, comprising blending an elastomeric composition    comprising the at least one propylene-based polymer comprising    propylene derived units and one or more dienes; at least one    component selected from the group consisting of multifunctional    acrylates, multifunctional methacrylates, functionalized    polybutadiene resins, functionalized cyanurate, and allyl    isocyanurate; and at least one component selected from the group    consisting of hindered phenols, phosphites, and hindered amines;    extruding the composition; and crosslinking the extruded polymer    using electron beam radiation having an e-beam dose of about 200 kGy    or less.-   3. The method of numbered embodiments 1 and 2, wherein the e-beam    dose is about 100 kGy.-   4. The method of any of the previous numbered embodiments, wherein    the e-beam dose ranges of from 40 kGy to about 60 kGy.-   5. The method of any of the previous numbered embodiments, wherein    the blended composition further comprises one or more secondary    elastomeric components.-   6. The method of any of the previous numbered embodiments, wherein    the propylene-based polymer has a heat of fusion from about 1 J/g to    about 70 J/g.-   7. The method of any of the previous numbered embodiments, wherein    the propylene-based polymer has a melting point of about 100° C. or    less.-   8. The method of any of the previous numbered embodiments wherein    the propylene-based polymer has a triad tacticity from about 60% to    about 97%.-   9. The method of any of the previous numbered embodiments, wherein    the propylene-based polymer further comprises units derived from an    alpha-olefin other than the propylene derived units and the one or    more dienes in an amount from about 5 wt % to about 40 wt %.-   10. The method of numbered embodiment 9, wherein the propylene-based    polymer comprises units derived from ethylene, 1-butene, 1-hexene    and/or 1-octene.-   11. The method of numbered embodiment 9, wherein the propylene-based    polymer comprises from about 5 wt % to about 40 wt % of units    derived from ethylene and/or 1-butene.-   12. The method of numbered embodiment 9, wherein the propylene-based    polymer comprises from about 5 wt % to about 40 wt % of units    derived from ethylene and/or 1-hexene.-   13. The method any of the previous numbered embodiments, wherein the    propylene-based polymer comprises from 0.2 to 4 wt %    5-ethylidene-2-norbornene (ENB).-   14. The method any of the previous numbered embodiments, wherein the    extruded article is a fiber, yarn, or film.

1. A method for making a crosslinked elastomeric article, comprising:blending an elastomeric composition comprising: at least onepropylene-based polymer comprising propylene derived units and one ormore dienes, the propylene-based polymer having a triad tacticity offrom 50% to 99% and a heat of fusion of less than 80 J/g; at least onecomponent selected from the group consisting of multifunctionalacrylates, multifunctional methacrylates, functionalized polybutadieneresins, functionalized cyanurate, and allyl isocyanurate; and at leastone component selected from the group consisting of hindered phenols,phosphites, and hindered amines; extruding the composition; andcrosslinking the extruded polymer using electron beam radiation havingan e-beam dose of about 200 kGy or less.
 2. The method of claim 1,wherein the e-beam dose is about 100 kGy.
 3. The method of claim 1,wherein the e-beam dose ranges of from 40 kGy to about 60 kGy.
 4. Themethod of claim 1, wherein the blended composition further comprises oneor more secondary elastomeric components.
 5. The method of claim 1,wherein the propylene-based polymer has a heat of fusion from about 1J/g to about 70 J/g.
 6. The method of claim 1, wherein thepropylene-based polymer has a melting point of about 100° C. or less. 7.The method of claim 1, wherein the propylene-based polymer has a triadtacticity from about 60% to about 97%.
 8. The method of claim 1, whereinthe propylene-based polymer further comprises units derived from analpha-olefin other than the propylene derived units and the one or moredienes in an amount from about 5 wt % to about 40 wt %.
 9. The method ofclaim 8, wherein the propylene-based polymer comprises units derivedfrom ethylene, butene, hexene and/or octene.
 10. The method of claim 9,wherein the propylene-based polymer comprises from about 5 wt % to about40 wt % of units derived from ethylene and/or butene.
 11. The method ofclaim 9, wherein the propylene-based polymer comprises from about 5 wt %to about 40 wt % of units derived from ethylene and/or hexene.
 12. Themethod of claim 1, wherein the propylene-based polymer comprises from0.2 to 4 wt % 5-ethylidene-2-norbornene (ENB).
 13. The method of claim1, wherein the extruded article is a fiber, yarn, or film.
 14. A methodfor making a crosslinked elastomeric article, comprising: blending anelastomeric composition comprising: at least one propylene-based polymercomprising propylene derived units and one or more dienes, thepropylene-based polymer having a triad tacticity of from 50% to 99% anda heat of fusion of less than 80 J/g; one or more polyolefinicthermoplastic components; at least one component selected from the groupconsisting of multifunctional acrylates, multifunctional methacrylates,functionalized polybutadiene resins, functionalized cyanurate, and allylisocyanurate; at least one component selected from the group consistingof hindered phenols, phosphites, and hindered amines; extruding thecomposition; and crosslinking the extruded polymer using electron beamradiation having an e-beam dose of about 100 KGy or less.
 15. The methodof claim 14, wherein the blended composition further comprises one ormore secondary elastomeric components, and wherein the one or morepolyolefinic thermoplastic components comprises isotactic polypropylene,random copolymer, and impact copolymer.
 16. A fiber made from thecomposition of claim
 14. 17. A crosslinked elastomeric composition,comprising: at least one propylene-based polymer comprising propylenederived units and one or more dienes, the propylene-based polymer havinga triad tacticity of from 50% to 99% and a heat of fusion of less than80 J/g; at least one component selected from the group consisting ofmultifunctional acrylates, multifunctional methacrylates, functionalizedpolybutadiene resins, functionalized cyanurate, and allyl isocyanurate;at least one component comprising trimethylolpropane trimethacrylate;one or more polyolefinic thermoplastic components; and optionally one ormore secondary elastomeric components, wherein the crosslinkedpolypropylene has great than 50% xylene insolubles as measured accordingto ASTM-D
 5492. 18. A fiber made from the crosslinked composition ofclaim
 17. 19. A film made from the crosslinked composition of claim 17.20. A film made from the composition of claim 14.